Microstructure and grain refining performance of a new Al-Ti-C-B master alloy

A kind of Al-Ti-C-B master alloy with a uniform microstructure is prepared using a melt reaction method. It is found that the average grain size of α-Al can be reduced from 3500 to 170 μm by the addition of 0.2 wt.% of the prepared Al-5Ti-0.3C-0.2B and the refining efficiency does not fade obviously within 60 min. It is considered that the TiCxBy and TiB2−mCn particles found at the grain center are the effective and stable nucleating substrates for α-Al during solidification, which accounts for the good grain refining performance.